World Energy Outlook 2007

demand. Improvements of up to 50% in the efficiency of gasoline and diesel
internal combustion engines, and even of full-hybrid vehicles, would also be
needed. Policies to promote hybrid technology could include vehicle-purchase
subsidies, regulatory standards and higher taxes on the least efficient vehicles.
Biofuels use in 2030 is twice as big as in the Alternative Policy Scenario, at
330 Mtoe. Given the constraints on land, water and biomass availability, this
level of production of biofuels could be achieved only through the large-scale
introduction of second-generation biofuels, based mainly on ligno-cellulosic
feedstock (IEA, 2006a). Energy use in non-power sector transformation –
including refineries and oil and gas extraction – is reduced by 16% over and
above the Alternative Policy Scenario, thanks to the reduced need to supply
hydrocarbons to end users.
5
Power Generation
To reach the overall 23 Gt target for 2030, emissions from the power sector
would need to be limited to 6.3 Gt, compared with 13.7 Gt in the Alternative
Policy Scenario and 18.7 Gt in the Reference Scenario. 11 Given the long lead
times in bringing new capacity on line in the power sector and the current
policy framework, we assume that the installed power generating capacity
follows the Alternative Policy Scenario trend until 2012. Even if no new power
plants were built after 2012 and taking retirements into account, emissions in
2030 would still be around 10 Gt. This is well in excess of the level compatible
with the 450 ppm of CO 2
-equivalent stabilisation target. Therefore, some of
the power plants in operation in 2012 would need to be retired before the end
of their economic lifetime and any new capacity added would need to be zerocarbon.
We calculate that some 15% of the fossil-fuel generating capacity
would need to be retired early between 2012 and 2030 on the assumption that
all new generating capacity is either nuclear power, renewables-based or, after
2015, fossil-based with CO 2
capture and storage (Figure 5.13). If retrofitting
of fossil-based generation with CCS was considered, the need for early
retirements would be lower (CCS is discussed later in this chapter).
Electricity demand in the 450 Stabilisation Case grows from 18 200 TWh in
2005 to 29 300 TWh in 2030, by 1.9% per year. Electricity generated by the
power plants in use in 2012 declines from 22 930 TWh in 2012 to
some 15 100 TWh in 2030. The balance comes from zero- or low-carbon
power plants – renewables, and nuclear power. After 2015 we assume
the gradual introduction of coal- and gas-fired power plants equipped with
CCS (Figure 5.14). As there is an infinite number of combinations of capacity
11. Implementation of energy-efficiency measures in end-use sectors at a higher cost than assumed
in this case ($50 per tonne of CO 2
) would increase energy and CO 2
-emissions savings in final
consumption, requiring less reductions in the power sector.
Chapter 5 - Global Environmental Repercussions 211